The present embodiments relate to a method for determining an irradiation plan.
Particle therapy is an established method for treating tissue (e.g., tumor diseases). Irradiation methods, as are used in particle therapy, are however also used in non-therapeutic fields. These non-therapeutic fields include, for example, research work for product development within the scope of particle therapy, the research work being performed, for example, on non-living phantoms or bodies or the irradiation of materials.
In these applications, charged particles such as, for example, protons or carbon ions or other ions are accelerated to high energies, shaped to form a particle beam and guided to one or more irradiation rooms by way of a high energy beam transportation system. In the irradiation room, the target volume to be irradiated is irradiated with the particle beam.
Irradiation methods referred to as scanning methods are known. With these methods, a particle beam with a small diameter compared to the target volume is guided successively to a plurality of destinations in the target volume; the target volume is “scanned” by the particle beam.
Methods of “inverse” irradiation planning are likewise known. With methods of this type, an irradiation target to be reached (e.g., a target volume to be irradiated, organs to be protected and a target dose to be achieved) is specified by a user. It is then determined how this specification can be implemented during an irradiation (i.e., how the parameters, with which an irradiation process can be controlled and which finally effect the dose deposition, are to be adjusted). For example, the dose portion to be applied, the direction from which the dose portion is to be applied and the area of the target volume to which the dose portion is to be applied are determined. The parameters that characterize the dose distribution depend on one another in a complex fashion. An inverse irradiation planning is thus usually implemented with an optimization algorithm, which takes these dependencies into account.